1. Field of the Invention
The present invention is related to a dental implant assembly and an abutment thereof, and more particularly is related to a dental implant assembly, which uses an elastic pressing structure to prevent relative rotation between the implant and the abutment and adopts the tolerance allowable gap between the fixing rod and the abutment fixing channel to overcome the interference issue due to offset errors between the implant and the abutment, and an abutment thereof.
2. Description of the Prior Art
The history of dental implant technology can be traced back to Medieval. The ancient Egyptian and South American civilization replace the missing teeth using carved ivory and wood. Starting from the 19th century, people stated to use different materials as dental implant, such as gold, platinum, ceramic, and Co—Cr—Mo alloy. Until the end of 20th century, dental implant technology was well developed with over 200 different dental implant assemblys.
FIG. 1 is a cross-section view of a dental implant assembly provided in accordance with the conventional technology. As shown, during the conventional dental implant surgery using the dental implant assembly PA1, an implant is placed in an alveolar bone PA2 (shown in FIG. 3) first. After a few months until the bone heals and the implant PA11 is firmly fixed in the alveolar bone PA2, the dentist will screw an abutment PA11 into a screw hole PA111 of the implant PA11 using a screw PA13 penetrating the abutment channel PA121 of the abutment PA12, and also decide the shape of the crown to be fixed on the abutment PA12 according to the dental structure.
However, because the dental implant assembly PA1 is a assembly with precision components, a slight difference may lead to a huge problem. FIG. 2 is a cross-section view showing a dental implant assembly having an abutment channel with tolerance provided in accordance with the conventional technology. As shown, if there is any angular or positional error happened in the abutment channel PA121′ of the abutment PA12′ during manufacturing, it is common to find that the screw PA13 passing through the abutment channel PA121′ cannot be aligned with the screw hole PA111 of the implant PA11, such that the abutment PA12′ cannot be fixed to the implant PA11 by using the screw PA13.
FIG. 3 is a cross-section view showing the dental implant assembly with three abutments as a unit screw-fixed on three different implants with errors in accordance with a conventional technology. As shown, when a dental implant surgery with multiple adjacent teeth is needed, the dentist may place three implants PA11, PA11a, PA11b into the alveolar bone PA2 first. After the healing period, the second procedure takes place to screw-fix the three abutments PA12, PA12a, PA12b jointed by the dental bridge to the implants PA11, PA11a, PA11b. 
It is common for the dentist to do the dental implant surgery using a guiding plate to place the implants PA11, PA11a, PA11b into the alveolar bone PA2. However, even with the assistance of tools, human errors, such as the position error or the angular error with 1 to 2 degrees during the implant placement process, are still unpreventable, such that the implants PA11, PA11a, PA11b may be unparalleled with each other when placed into the alveolar bone PA2. Meanwhile, the relative position and angle between the abutments PA12, PA12a, PA12b are not adjustable because these abutments PA12, PA12a, PA12b are jointed by the dental bridge PA3. Under such restriction, it would be difficult to screw-fix the abutments PA12, PA12a, PA12b jointed by the dental bridge PA3 as a unit on the implants PA11, PA11a, PA11b simultaneously due to the misalignment among the implants PA11, PA11a, PA11b when placing the artificial teeth, and would be also difficult to remove the screw-fixed abutments PA12, PA12a, PA12b jointed by the dental bridge PA3 as a unit from the implants PA11, PA11a, PA11b. 